Effects of Gemcitabine or Gefitinib on NK cell-mediated cytotoxicity and NK cell degranulation.

<p>(Ai): A549 cells with or without Gemcitabine (GEM) (10 nM) for 24 hours were subjected to LDH release assay for 4 hours using IL–2 activated NK cells as effector cells. The IL–2 activated NK cells were pretreated with blocking antibody of NKG2D or isotype control for 30 min before the cytotoxicity assay. Data are presented as mean of triplicate samples and are representative of three independent experiments. (ii): IL–2 activated NK cells were pretreated with blocking antibody of NKG2D or isotype control before NK cell degranulation assay, then coincubated with A549 cells treated with or without GEM for 4 hours, and NK cell degranulation was evaluated. (Bi): PC–9 cells with or without Gefitinib (Gef) (1 μM) were subjected to LDH release assay for 4 hours using IL–2 activated NK cells as effector cells. Data are presented as mean of triplicate samples and are representative of three independent experiments. (ii): IL–2 activated NK cells were coincubated for 4 hours with PC–9 cells pretreated with or without Gefitinib, and NK cell-degranulation was evaluated. Data are representative of three independent experiments. E:T ratio; effector/target ratio.